<?
$db = new MySQLi('localhost', 'root', 'pass', 'baza');
$pInfo = $db->query('SELECT `players`.`id`, `players`.`lastlogin` FROM `players`;')->fetch();
$hInfo = $db->query('SELECT `houses`.`id` FROM `houses` WHERE `houses`.`owner` = '.$pInfo['id'].';');
if($hInfo->rowCount())
if($pInfo['lastlogin'] < (time() - 24 * 3600))
$db->query('UPDATE `houses` SET `houses`.`owner` = 0 WHERE `houses`.`owner` = '.$pInfo['id'].';');
$db->close();
?>